static int num_fault_mutexes;
static struct mutex *htlb_fault_mutex_table ____cacheline_aligned_in_smp;
+/* Forward declaration */
+static int hugetlb_acct_memory(struct hstate *h, long delta);
+
static inline void unlock_or_release_subpool(struct hugepage_subpool *spool)
{
bool free = (spool->count == 0) && (spool->used_hpages == 0);
spin_unlock(&spool->lock);
/* If no pages are used, and no other handles to the subpool
- * remain, free the subpool the subpool remain */
- if (free)
+ * remain, give up any reservations mased on minimum size and
+ * free the subpool */
+ if (free) {
+ if (spool->min_hpages != -1)
+ hugetlb_acct_memory(spool->hstate,
+ -spool->min_hpages);
kfree(spool);
+ }
}
-struct hugepage_subpool *hugepage_new_subpool(long nr_blocks)
+struct hugepage_subpool *hugepage_new_subpool(struct hstate *h, long max_hpages,
+ long min_hpages)
{
struct hugepage_subpool *spool;
spin_lock_init(&spool->lock);
spool->count = 1;
- spool->max_hpages = nr_blocks;
+ spool->max_hpages = max_hpages;
+ spool->hstate = h;
+ spool->min_hpages = min_hpages;
+
+ if (min_hpages != -1 && hugetlb_acct_memory(h, min_hpages)) {
+ kfree(spool);
+ return NULL;
+ }
+ spool->rsv_hpages = min_hpages;
return spool;
}
return NULL;
}
+/*
+ * Test to determine whether the hugepage is "active/in-use" (i.e. being linked
+ * to hstate->hugepage_activelist.)
+ *
+ * This function can be called for tail pages, but never returns true for them.
+ */
+bool page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHuge(page), page);
+ return PageHead(page) && PagePrivate(&page[1]);
+}
+
+/* never called for tail page */
+static void set_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ SetPagePrivate(&page[1]);
+}
+
+static void clear_page_huge_active(struct page *page)
+{
+ VM_BUG_ON_PAGE(!PageHeadHuge(page), page);
+ ClearPagePrivate(&page[1]);
+}
+
void free_huge_page(struct page *page)
{
/*
restore_reserve = true;
spin_lock(&hugetlb_lock);
+ clear_page_huge_active(page);
hugetlb_cgroup_uncharge_page(hstate_index(h),
pages_per_huge_page(h), page);
if (restore_reserve)
copy_user_huge_page(new_page, old_page, address, vma,
pages_per_huge_page(h));
__SetPageUptodate(new_page);
+ set_page_huge_active(new_page);
mmun_start = address & huge_page_mask(h);
mmun_end = mmun_start + huge_page_size(h);
}
clear_huge_page(page, address, pages_per_huge_page(h));
__SetPageUptodate(page);
+ set_page_huge_active(page);
if (vma->vm_flags & VM_MAYSHARE) {
int err;
#ifdef CONFIG_MEMORY_FAILURE
-/* Should be called in hugetlb_lock */
-static int is_hugepage_on_freelist(struct page *hpage)
-{
- struct page *page;
- struct page *tmp;
- struct hstate *h = page_hstate(hpage);
- int nid = page_to_nid(hpage);
-
- list_for_each_entry_safe(page, tmp, &h->hugepage_freelists[nid], lru)
- if (page == hpage)
- return 1;
- return 0;
-}
-
/*
* This function is called from memory failure code.
* Assume the caller holds page lock of the head page.
int ret = -EBUSY;
spin_lock(&hugetlb_lock);
- if (is_hugepage_on_freelist(hpage)) {
+ /*
+ * Just checking !page_huge_active is not enough, because that could be
+ * an isolated/hwpoisoned hugepage (which have >0 refcount).
+ */
+ if (!page_huge_active(hpage) && !page_count(hpage)) {
/*
* Hwpoisoned hugepage isn't linked to activelist or freelist,
* but dangling hpage->lru can trigger list-debug warnings
bool isolate_huge_page(struct page *page, struct list_head *list)
{
+ bool ret = true;
+
VM_BUG_ON_PAGE(!PageHead(page), page);
- if (!get_page_unless_zero(page))
- return false;
spin_lock(&hugetlb_lock);
+ if (!page_huge_active(page) || !get_page_unless_zero(page)) {
+ ret = false;
+ goto unlock;
+ }
+ clear_page_huge_active(page);
list_move_tail(&page->lru, list);
+unlock:
spin_unlock(&hugetlb_lock);
- return true;
+ return ret;
}
void putback_active_hugepage(struct page *page)
{
VM_BUG_ON_PAGE(!PageHead(page), page);
spin_lock(&hugetlb_lock);
+ set_page_huge_active(page);
list_move_tail(&page->lru, &(page_hstate(page))->hugepage_activelist);
spin_unlock(&hugetlb_lock);
put_page(page);
}
-
-bool is_hugepage_active(struct page *page)
-{
- VM_BUG_ON_PAGE(!PageHuge(page), page);
- /*
- * This function can be called for a tail page because the caller,
- * scan_movable_pages, scans through a given pfn-range which typically
- * covers one memory block. In systems using gigantic hugepage (1GB
- * for x86_64,) a hugepage is larger than a memory block, and we don't
- * support migrating such large hugepages for now, so return false
- * when called for tail pages.
- */
- if (PageTail(page))
- return false;
- /*
- * Refcount of a hwpoisoned hugepages is 1, but they are not active,
- * so we should return false for them.
- */
- if (unlikely(PageHWPoison(page)))
- return false;
- return page_count(page) > 0;
-}